(CNSNews.com) – Transgenders in the U.S. military? “I do think it continually should be reviewed,” Defense Secretary Chuck Hagel said in an interview that aired Sunday on ABC’s “This Week.”

“I'm open to that, by the way. I'm open to those assessments because, again, I go back to the bottom line. Every qualified American who wants to serve our country should have an opportunity if they fit the qualifications and can do it. This is an area that we've not defined enough.”

Hagel told ABC’s Martha Raddatz the transgender issue is “a bit more complicated” than homosexuals in the military “because it has a medical component to it. These issues require medical attention,” Hagel said.

“Austere locations where we put our men and women in many cases don't always provide that kind of (medical) opportunity.”

Raddatz also asked Hagel how difficult it will be for the U.S. to locate the hundreds of Christian girls abducted in Nigeria.

“It's going to be very difficult. It's a vast country,” Hagel said. “So this is not going to be an easy task, but we're going to bring to bear every asset we can possibly use to help the Nigerian government.

Hagel said the U.S. has no intention of putting “any American boots on the ground.”